Gas Estimator
Estimate transaction costs for common blockchain operations
Understanding Gas Fees
Gas is the unit of computational effort required to execute operations on the Ethereum blockchain. Every transaction and smart contract execution requires gas, which you pay for in ETH.
How Gas Works
When you send a transaction, you specify two key parameters:
- Gas Limit: Maximum gas you're willing to use
- Gas Price: How much you're willing to pay per unit of gas (in Gwei)
The total transaction fee is calculated as:
Transaction Fee = Gas Used × Gas Price
Gas Limit vs Gas Used
The gas limit is the maximum amount you're willing to spend, but you only pay for what's actually used. If your transaction uses less gas than the limit, the excess is refunded.
Example
You set a gas limit of 50,000 at 30 Gwei:
- Maximum possible cost: 50,000 × 30 = 1,500,000 Gwei (0.0015 ETH)
- If only 35,000 used: 35,000 × 30 = 1,050,000 Gwei (0.00105 ETH)
- Refunded: 15,000 × 30 = 450,000 Gwei (0.00045 ETH)
Typical Gas Costs
| Operation | Typical Gas | Description |
|---|---|---|
| ETH Transfer | 21,000 | Simple transfer between wallets |
| ERC-20 Transfer | 65,000 | Transfer tokens |
| ERC-20 Approve | 45,000 | Approve spending allowance |
| Uniswap Swap | 150,000-180,000 | Swap tokens on DEX |
| NFT Mint | 100,000 | Mint a new NFT |
| NFT Transfer | 85,000 | Transfer NFT ownership |
| Contract Deploy | 300,000+ | Deploy smart contract |
Gas Price Strategy
When to Use Different Gas Prices
- Low (10-20 Gwei): Non-urgent transactions, can wait hours
- Average (30-50 Gwei): Normal priority, confirmed in minutes
- High (50-100 Gwei): High priority, fast confirmation
- Urgent (100+ Gwei): Time-sensitive, nearly instant confirmation
EIP-1559 Gas Model
Since August 2021, Ethereum uses EIP-1559, which changed how gas fees work:
Base Fee
The minimum fee required to include a transaction, burned (removed from circulation) rather than paid to miners.
Priority Fee (Tip)
Additional fee to incentivize miners to include your transaction faster. Goes directly to miners/validators.
Max Fee
Maximum total you're willing to pay per gas. Formula:
Total Fee = (Base Fee + Priority Fee) × Gas Used
Gas Optimization Tips
For Users
- Check gas prices before transacting (use gas trackers)
- Transact during low-activity periods (weekends, late nights UTC)
- Consider Layer 2 solutions for lower fees
- Batch multiple transactions when possible
- Set appropriate gas limits (not too high, not too low)
For Developers
- Optimize smart contract code to use less gas
- Use efficient data structures and algorithms
- Minimize storage operations (most expensive)
- Batch operations when possible
- Consider upgradeable contracts for efficiency improvements
Layer 2 Solutions
To reduce gas costs, consider using Layer 2 networks:
- Arbitrum: Optimistic rollup with low fees
- Optimism: Another optimistic rollup
- Polygon: Sidechain with fraction-of-a-cent fees
- zkSync: Zero-knowledge rollup
- Base: Coinbase's L2 solution
Gas Price Guide
Current Recommendations
- Low: 10-20 Gwei
- Average: 30-50 Gwei
- High: 50-100 Gwei
- Urgent: 100+ Gwei
Check Live Prices
Quick Tips
- Gas limit is maximum, not actual cost
- Unused gas is refunded
- Failed transactions still cost gas
- Complex operations cost more gas
- Storage operations are expensive
- Reading data is free (view functions)